The long-term effects of the Lacey Act Amendment on high-risk timber species: insights from 15 years of interrupted time series analysis

Despite comprising a small portion of US wood consumption, tropical hardwoods like Keruing and Meranti are highly valued for their aesthetic and physical properties. However, their sustainability is threatened by illegal logging and over-harvesting, compounded by the use of generic names that obscure species identities, complicating trade monitoring and regulation. Enacted in May 2008, the Lacey Act Amendment (LAA) aims to ensure the legality of plant and plant product sourcing in the US. This study evaluates the LAA’s impact on the import of these tropical hardwoods from Indonesia and Malaysia, hypothesizing that the amendment has curtailed illegal imports, thereby reducing import volumes and increasing prices. Using data from 1990 to 2023, we employed (i) intervention multiple regression analysis with autoregressive error and (ii) intervention auto-regressive integrated moving average models with step transfer function to analyze changes in import trends. Findings indicate that while LAA has significantly impacted import trends as anticipated, the effects are complex and evolving over time, highlighting the need for ongoing regulation analysis and enforcement monitoring. This research underscores the critical role of targeted legal frameworks in promoting sustainable trade practices and conservation, offering valuable insights for policymakers aiming to combat exploitative and illegal logging globally.